Using Geophysical Method for Saline Soil Remediation

Alongside soil degradation by salinization, several salt-affected soils are reclaimed. In semi-arid areas, this reclamation is improved by rains and different operations such as drainage and irrigation with fresh or brackish waters. According to these natural and human actions, the desalinization of the soils is happened until the salinity level is adapted to crop tolerance. Thus, the speed salt dynamic and the spatio-temporel salt distribution are very important to know in purpose to adapt the agricultural scheme by the farmers. In parallel, the leaching of salt under the topsoil (> 1.2 m) is also very important. This leached salt will lead to the salinization of the aquifer, when the irrigated areas have a water table whose water is pumped for irrigation. This situation is the case of the selected area of Kairouan. The geophysical method is used for soil salinity assessment. Salinity prediction was performed by using two complementary electromagnetic (EM) induction instruments: EM38 for arable layer (0–1.2 m) and EM31 for deep layer (0–6.0 m). A multiple linear regression was established between the measured soil electrical conductivity of saturated paste extract (ECe) and the apparent electrical conductivity (ECa). The ECa-EM38 has been shown to be optimal in ECe prediction of surface soil. The soil salinity spatial structure was relatively unchanged. However, the temporal variability of soil salinity at the soil surface is greater than at the depth. These maps have been used to identify spatial and temporal features that can be managed efficiently.